November 2012

TC work central to hydropower success

The clean power of water

Hydropower continues to be the main source of clean energy in the world. Worldwide, it accounted for 16% of overall electricity generation and for 81,6% of electricity generation from renewable sources in 2010, according to the IEA (International Energy Agency) World Energy Outlook 2012. This rather mature technology covers both large and small installations and offers great flexibility as it can respond immediately to on-demand compensations for generation and grid variances. It can also help regulate or make up for shortfalls in power generated from intermittent sources such as solar and wind. IEC TC (Technical Committee) 4: Hydraulic turbines, prepares International Standards for hydropower installations.

Senior TC, but ever more relevant

Created in 1913, IEC TC 4 is one of the IEC's first TCs. It is "responsible for the preparation, periodic review and updating of standards and technical reports covering the design, manufacturing and rehabilitation, commissioning, installation, testing, operation and maintenance of hydraulic machines including turbines, storage pumps and pump turbines of all types as well as related equipment".

The demand for large quantities of clean renewable world energy, including extending the life of valuable existing equipment and properly integrated water management has never been so great [see article on hydropower in e-tech, January 2012].

Today, more than 125 technical experts experts from 34 countries take part in TC 4 work. More than half of these experts regularly attend TC 4 plenary meetings, typically held every 2 years, on a regular basis

Both large and small hydropower installations

Hydropower, the power derived from the energy of flowing or falling water, had been used for centuries to drive various mechanical devices before being harnessed to produce electricity in the late 19th century. Today, the term is used almost exclusively for hydroelectric power.

Hydroelectricity is generated in over 160 countries and for most people it is associated with large dams and reservoirs and very high capacities that can reach up to 22,5 GW (for the recently-completed Three Gorges Dam in China).

However, small, micro- and pico-hydro stations can also play an important role, in particular in certain countries and environments, and in remote and rural off-grid locations. Micro-hydro schemes can be as large as 500 kW and are generally run-of–the-river developments for villages. Pico-hydro systems are generally used for individuals or clusters of households.

Realizing that small hydro projects had their own requirements, TC 4 prepared IEC 61116, Electromechanical equipment guide for small hydroelectric installations.

TC 4 also published IEC 62006, Hydraulic machines –Acceptance tests of small hydroelectric installations. This International Standard "defines the test, measuring methods and the contractual guarantee conditions for field acceptance tests of the generating machinery in small hydroelectric power installations. It applies to installations containing impulse or reaction turbines with unit power up to about 15 MW and reference diameter of about 3 m".

Beyond electricity production

In its "Directions in Hydropower" document, the World Bank acknowledges the importance of hydropower beyond its traditional role of providing electricity. It stresses that hydropower is also viewed now as an integral factor in addressing energy security, climate change, water security and regional cooperation. In addition, the report highlights the fact that hydropower resources can be harnessed for poverty alleviation and sustainable development.

Hydroelectric dams will play a significant role in managing water resources, an issue set to become more important in the medium to long term as access to water becomes increasingly difficult in many regions of the world.

As many countries seek to increase the share of renewable sources in their energy mix, hydropower – pumped storage in particular – which makes up 99% of worldwide installed storage capacity for electrical energy, will play a central role in regulating the production, distribution and storage of energy from intermittent sources such as solar and wind (see article on pumped storage in this issue)

Extensive domain, no rest in sight

The potential for additional hydropower, especially in Africa, Asia and Latin America, is considerable, according to an October 2012 joint Technology Roadmap report on hydropower by the IEA and the Brazilian Mines and Energy Ministry.

The roadmap "foresees, by 2050, a doubling of global capacity up to almost 2 000 GW and of global electricity generation over 7 000 TWh. Pumped storage hydropower capacities would be multiplied by a factor of 3 to 5".

TC 4 publications cover all areas of hydropower installations and include the following:

field acceptance testing

model acceptance testing

speed governing and controls

cavitation of hydro machines

commissioning, operation and maintenance

vibrations in hydraulic machines

small hydro installations

hydraulic turbine control

nomenclature for hydroelectric power plant machinery

tendering documents

scale effects from model

flow measurements

small hydro acceptance tests

particle erosion of machines

hydropower equipment installation

rehabilitation and performance improvement and life assessment

Given the huge global hydropower potential that has yet to be exploited and the need for optimized International Standards, IEC TC 4 experts, who work on an extremely wide scope of activities, will have a very busy agenda for the foreseeable future

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TC 4 plenary meeting (Tokyo, Japan, October 2012)

Kaplan turbine in hydroelectric power plant on the river Weser in Bremen, Germany